In recent years, compactness, high output, and increased efficiency have been required in rotary electric machines such as electric motors or generators. With regard to downsizing rotary electric machines of this kind, stator windings that have concentrated windings in which conductor wires are wound onto individual stator core teeth have been used with a view to downsizing coil ends, which do not generate effective magnetic flux. However, stators that use distributed winding stator windings are in demand because increases in output are possible using distributed winding stator windings compared to concentrated winding stator windings.
Excitation currents are also becoming larger with increases in output. In order to cope with larger excitation currents, there is a tendency to use conductor that have a large cross-sectional area and conductor wires that have a rectangular cross section, and there is demand to manufacture coils so as to machine such conductor wires, which have higher rigidity, accurately and without damaging insulating coatings that are coated onto the conductor wires.
Here, in contrast to concentrated windings, which are configured by winding conductor wires onto individual teeth, windings that are configured by winding conductor wires into slots that are separated by two or more slots are called “distributed windings”.
In Patent Literature 1, coil end portions that connect rectilinear portions together with rectilinear portions that are housed in different slots circumferentially are formed on a conductor wire, and then the conductor wires on which the rectilinear portions and the coil end portions are formed are wound onto a cylindrical inner pressing member with displacement of the rectilinear portions restricted, and then a pressing member is pressed onto the coil end portions from radially outside, to form crank portions on the coil end portions, and also to form the coil end portions to a set curvature.